It is always a problem to keep fresh foods requiring refrigeration cold especially when a refrigerator device is not available. It is highly difficult to make the refrigerator device portable. An electro-mechanical refrigerator device is too heavy, and additionally requires a power source, which also adds to the weight thereof, so as to minimize portability.
A disposable refrigerant cannot accomplish the desired refrigeration. Ice does melt and can cause difficulty in keeping an area appropriately clean--among other problems. Frozen carbon dioxide (commonly known as dry ice), while eliminating the water problem, is too bulky, which adds to the difficulty of carrying the portable refrigerator.
Reusable refrigerants and containers therefor do not solve the problem when the item to be carried is of a substantial size. Most such containers are not large enough to carry the desired amount of food. Furthermore, the size of the container having a sufficient amount of reusable refrigerant to carry a large amount of food, prohibits easy refreezing of the container. It is difficult also to even cool a large reusable container.
Also, with the size of various food containers such as those for salads and similar matters a refrigeratable container becomes too large to handle appropriately. It is desired therefor to provide a refrigeratable means capable of easily being transported while at the same time maintaining the desired cool area for the desired size of the food container.
This is especially in view of the fact of the current trends. The current trends in foods and eating include eating lighter and more natural foods to provide balanced nutrition and lower amounts of added fats and salts. This is clearly a major part of the overall fitness and health trend especially here in the United States.
A primary means of achieving satiaton without overindulging in fats and carbohydrates is to eat perishable, fresh food such as fresh fish, vegetables and fruits that are rich in nutrients and fiber. The fiber provides bulk which makes the consumer feel full, but without adding excess calories. The fiber is also a stimulant to the bodily functions in view of the fact that it is not broken down in the digestive process.
A primary way for deivering these desired foods to a person is in the form of a salad. Other additives can be put into the salad. Meat, fruit, vegetables and other items can be added to a salad. A wide array of fruits and vegetables in a salad provides a complete, pleasing and crisp texture which in turn provides for satisfied chewing. The satisfied chewing increases the enjoyment of the food and encourages consumption of this very healthful food.
Because salads are served in their natural state, the heat or dry air of a household or outdoor picnic can cause wilting and discoloration. This negative factor reduces the physical and nutritional appeal of the food. Chilling is the way to avoid this problem. It is difficult to do however. Furthermore, because salads are often tossed in large containers, it is difficult to store a large container in a refrigerator and keep it cool. It is highly desirable to be able to keep a large container cool in order to preserve the stability of the food to be eaten.